Holidays are the season for nostalgia. Without fail, reference to the “good old days” often turns into debates over contemporary headaches.
Whatever the topic (crime, taxes,popular music, etc.), everyone seems to think it must have been better way back when.

But that’s not always the case. Consider obesity.

Many health officials criticize the modern American diet, suggesting that our grandparents’ nutrition was notably superior. In reality, most people in the ‘50s and ‘60s ate a high-fat, high-cholesterol and high-sugar diet. Local grocers sold only full-fat versions of dairy products. Most recipe books listed lard-a solid block of pig fat-as a cooking staple. And dinner in many households consisted of the standard meat and potatoes. Few of these dietary habits met today’s threshold for “healthy.”

Sure, there have been some changes between our meals and those of our grandparents. But the most radical transitions over the past decades have transpired not in our cooking, but in other pastimes. At home, in the office and on the road, technology’s influence on our waistlines is undeniable. But the food-only focus distracts the public from a larger issue-our activity-free lifestyles.

Suburbia, appliances, and thousands of TV channels: these and other largely overlooked factors play a big role in our weight gain.

Car travel is already considered one of the biggest contributors to weight gain, but the car itself-not just the trips-also adds to the problem. Power steering, power windows, and other modern technologies have made driving even more sedentary than it used to be. One study found that every additional hour spent in the car increases a person’s risk of obesity by six percent.

It may sound trivial. Yet, even a small convenience that keeps us from burning 50 calories each day-like emailing a co-worker instead of walking to her office-can tack on more than five pounds annually.

Inactivity doesn’t just make us fat. It’s deadly, too. According to researchers at the University of Missouri, people who exercise live 3.5 years longer than sedentary people. And a recent study in the Journal of the American Medical Association showed that being out of shape increases our risk of early death more than our weight.

The growing epidemic of physical inactivity and its related diseases are such a significant problem that U.S. doctors have coined a new term: Sedentary Death Syndrome. As the third leading cause of death, it claims the lives of 250,000 Americans each year. Basically, your couch is more likely to kill you than either a stroke or an accident.

Most Americans remain unaware of this threat. Caution about our sedentary lifestyles has been drowned out by warnings about America’s “killer” diet.

After all, it’s easy for activists to convince people that take-out is to blame for their love-handles. Personal responsibility is a much harder pill to swallow.